Highway crossing signal system



1937. A. T. CARTER 2,088,837

HIGHWAY CROSSING SIGNAL SYSTEM Filed May 15, 1931 ATTORNEY Patented Aug, 3, 1937 UNIT ED STAT PATENT OFFICE Application May 15, 1931, Serial No. 537,665

. 1 Claim.

This invention relates in general to highway crossing Signals for railway use,and has more particular reference toan improved highway crossing signal giving a plurality of difierent 5 colored aspects flashing at different rates,

In highway crossing protection it is desirable to provide means to arrest the attention of highway trafi'ic in a very certain manner, and furthermore to do this in the most economical manner 10 possible.

With the above and other objects in mind, it is proposed, in accordance with this invention, to provide a two-aspect color light signal at each side of a railway track where it is crossed by a 15 highway; proceed conditions being indicatedby one color, and stop conditions by a diiierent color.

It is further proposed to cause the light indications to flash, with the proceed indicationflashing at a slower rate than the stop indication, andto have the energized period of the proceedi'ndicat'ion shorter than that of the stop indication. provides a further distinction in addition to the difference in color, between 25 the difierentlaspects, and furthermore economiz esin power consumption and in mechanical wear on "the various moving parts.

' Further objects, purposes and characteristic section' has connected across one end of it a-= source" of track circuit energy'in the form of a batteryS with a limiting resistance 4 inseries therewith.

Connected across theother'ends of the track sections C and D are interlocked relays IR and" 501R? which can be of any usual or desired form;

such, for instance, as shown in the application to 0.5" S. Field, Ser. No; 474,958, filed August 13',

1930. i If desired, these interlocked relays can' be connected up to repeat" the" operation of usual 55K track relays.

Crossing the railway track is a highway H, and at each side of the highway, adjacent the track,. is a highway signal, which can be of any usual ordesired form, but is preferably of the form diagrammatically shown, and described in detail in application 470,056 of O. S. Field filed July 23, 1930. Each signal comprises a permanent magnetic field 5, an electro-magnetic armature 6, a spectacle 1 carrying colored roundels R and G, colored respectively red and green, and a light source 8; This light signal has the spectacle 1 biased, in any desired manner, to position the red glass in front of the light source 8,. when armature 6 is de-energized, and to position the green glass in front of the light source 8, when armature 6 is energized.

For controlling the flashing of the light sources 8', there is provided .a flashing relay FL, which is ofthe type shown in application 452,666 of O. S. Field, filed' May 15, 1930. In the form diagrammatically shown in the drawing, this relay ineludes a three-legged core 9, with the outer legs carrying series windings 29' and 30, and the middle leg carrying a separate choke winding l4 and copper washers I4 The relay FL has a pivoted armature II], for operating contact fingers in a manner to be described below in detail.

For controlling theduration of the energized periods of the light sources 8, there is employed a slow acting means, in the form of a relay SR.

The va'rio'usparts are shown in the drawing in' the positions and conditions existing when neither of the track sections C'and D is occupied. With neither track section occupied, the interlocked relays IE and IR are both energized which results in energizing the armature of each of the light signals, to thereby position the green glass in front of the light source,'said armatures being energized through a circuit including one terminal of a source of energy, contact fingers II and I2 and front points of the interlocked relays, and wire [3.

With' the interlocked relays energized, the, choke winding M on the center leg of the flashing relay is short-circuited through a circuit including, the contact fingers I5 and I6 and front points of the interlocked relays, whereby to decrelasethe rate of operation of the'flashing relay from the rate existing when the choke winding I4 is on open" circuit.

A bell B is provided, which is energized through a circuit which is obvious from the drawing, and includes either of the contact fingers l1 orl8, and their back points, of the interlocked' relays; whereby, with the track sections unoccupied, so that the interlocked relays are energized, the bell is de-energized.

The slow acting relay SR, is shown as energized. through a circuit which includes one terminal of a source of energy, contact fingers I 9 and 20 and front points of the interlocked relays, wire 2|, contact finger 22 and back point of relay FL, and the winding of relay SR.

In the condition of the parts as shown in the drawing, the light sources 8 are de energized, since their energizing circuits, which include wires 23 and.- 24 in multiple, wire 25, contact,

finger 26 and back point of relay SR, wire 21, and contact finger 28 and back 'point'of relay 15 FL, is open at the contact fingers 26 and 28. 7 As shown in the drawing, the winding 29 of relay FL, is shunted out of its energizing circuit, whereby to cause the flux in the relay core which is holding the armature l0 in'the'shown'posi- 20 tion, to die down at a rate dependent upon the inductance in its circuit, or, in other words, at a slower rate with the choke winding l4 closed, than is the'case when choke winding His open.

The flux produced by the otherend winding 25 30 of relay FL, operates to rock armature l0 to' its reverse energized position, and thereby" positions shown in the'drawing, to thereby pick,

up relay SR, and break the energizing circuits 40 for the light sources at the contact fingers 26 and 28.

It should be noted that completion of the energizing circuits for the light sources requires not only that theflashing relay FL shall op- 45 erate, but that the slow releaserelay SRshall release, andhence the .portion of 'a complete cycle during which each'light source is ener-' gized, under proceed conditions, is considerably less than one-half of the total time of the cycle, 50 and can be made as short asdesired, simply by increasing the release time of relay SR.

Upon one of the track sections C or D becoming occupied, one or the other of the interlocked relays releases its contact fingers, to thereby 55 complete the energizing circuit for the bell B, as is obvious from the drawing, to thus cause'the bell to sound.

The release of one of the contact fingers I or-|6, opens circuits the choke coil M of relay 60 FL, to thereby increase the rate of operation of its armature I 0 and various contact'fingers.

The release of one of the contact fingers I!) or 20, opens the energizing circuit for the slow 70 The release of either of the fingers II in l2 of the interlocked relays, de-energiz'es the armatures of the two highway crossing signals, to thereby cause the spectacles 7 to move by gravity, or any other desired means-to position the 1| red color glasses in front of the lightsourcesf With the track occupied, the flashing relay FL reverses the positions of its contact fingers 22, 28, 3| and 32. The opening and closing of contact finger 22 on its back point, has no eifect on relay SR, since this relay is already de-energized by the release of one of the contact fingers I9 or 20.

The closing of contact finger 28 of relay FL on its back point, closes the energizing circuits for the light sources 8, and thus causes the signals to flash.

-- It should be noted, in the case of danger conditions, thatthe flashing relay FL operates at a proceed conditions, and that the portion of a complete cycle during which the light sources are energized, is greater than in the first case considered where the track sections 0 and D were unoccupied, since under danger condition,

thatportion of the time when the light source is de-energized, which is introduced by the slow acting relay SR, iseliminated, so that the light sources are energized all the time that contact finger 28is closed on its back point.

It will thus be seen that the flashing of the green signal is less rapid than is the flashing or the red, and furthermore, that the green signal is energized a smaller portion of the flashing cycle than is the red signal. In as much as proceedconditions will be present the greater portion of the time, the slower flashing of the green signal operates to very greatly reduce the mechanical wear of the various moving parts in the flashing relay FL. Furthermore, since the green signal is displayed the greater portion of the time, a very decided saving in energy consumption is effected by reducing the portion of the flashing cycle during which it is energized. As a result economies are efiected both in mechanical wear and power consumption.

It is of course obvious that the rates of flashing of the two signals can be varied at will, and the durations of the energization can be varied at will,'by varying the choke coil l4, and the release characteristics of the slow release relay SR. In one form, which has been found very satisfactory, the choke winding l4 resulted in decreasing the rate of operation of. the flashing relay, when on closed circuit, to approximately one-half of, its rate when thewinding M was open circuited' In this form the'relay SR was adjusted to give a duration of energization of the green signal of approximately one-half that of the red signal.

It should be noted that the relay SR can be given any desired characteristics, so long as its release time is made less than the time during which contact finger 28 of relay FL remains in contact with its back point, it being clear that if the release time of relay SR be greater than this, no energization of the green signal can occur.

If a signal of the wigwag type should be desired, it isobvious that two signals can be supplied at eachside of they highway, with the additional signals operated from corresponding front points, as 50 and 5|, of relay FL, together with an additional slow release relay, connected to be energized through 50, for controlling the same.

'The above rather specific description of varicusforms of devices embodying the present invention, has been given solely by way of illustration, and is not intended, in any manner whatsoever, in a limiting sense. Obviously, this in- 10 played, a flashing relay having means to cause its armature to intermittently pick up and re: lease a choke winding on the flashing relay to vary its rate of operation, a slow release relay having an energizing circuit controlled by the flashing relay, and an energizing circuit for the light source including a back point of the slow release relay and a contact finger and point of the flashing relay.

AINSLIE T. CARTER. 

